Field Crops Research最新文献

{"title":"The split injection of water-soluble fertilizers effectively reduces N2O, CH4 and NH3 emissions while simultaneously improving rice yield and harvest index","authors":"","doi":"10.1016/j.fcr.2024.109637","DOIUrl":"10.1016/j.fcr.2024.109637","url":null,"abstract":"<div><div>Mitigating environmental impacts while enhancing grain yield is essential for sustainable rice production. One-time urea deep placement (UDP) has been recognized for its potential to reduce nitrogen (N) loss and improve rice yield. However, this method applies an excessive amount of nitrogen as a basal fertilizer, which increases N₂O emissions during the mid-season aeration (MSA) phase and promotes straw biomass over grain yield, consequently reducing the harvest index (HI). The split injection of water-soluble fertilizers (IF) could present a viable alternative solution. Nevertheless, no studies have yet investigated the environmental and agronomic effects of IF in rice production fields. Therefore, a three-year field experiment was conducted with six treatments: three-split urea broadcasting (BU), one-time UDP (UDP(10:0)), one-time IF (IF(10:0)), two-split IF with a 6:4 ratio (IF(6:4)), two-split IF with a 5:5 ratio (IF(5:5)), and a control without N (CK) in an intensive rice cropping system in China. Results showed that one-time UDP produced the lowest HI and increased N₂O emissions by 146 % compared to BU, due to surplus N provision until the MSA stage. In contrast, two-split IF treatments increased straw biomass by 7 %-9 % while improving rice yield by 13 %-14 % compared to BU and resulting in the highest HI, due to the reduced injection dosage of basal fertilizer and sufficient spike fertilizer injection, which in turn avoided surplus N at the MSA stage, thus decreasing total N₂O emissions by 15 %-28 % compared to BU. All deep fertilization treatments reduced CH₄ emissions by 43 %-67 % compared to BU. All IF treatments produced the parallel highest net economic benefit (NEB) of all treatments. Moreover, IF(6:4) reduced greenhouse gas intensity (GHGI) by 56 % compared to BU, and completely eliminated NH₃ volatilization. In conclusion, a two-split IF with a basal and spike fertilizer ratio of 6:4 is a promising strategy for reducing GHGI and NH₃ emissions while simultaneously improving rice yield, HI and NEB in paddy rice fields. Expanding split IF technology will greatly contribute to the green development of rice production.</div></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating wheat partitioning coefficient using remote sensing and its coupling with a crop growth model","authors":"","doi":"10.1016/j.fcr.2024.109620","DOIUrl":"10.1016/j.fcr.2024.109620","url":null,"abstract":"<div><h3>Context</h3><div>Accurately estimating the partitioning of daily photosynthetic assimilates among different plant organs is crucial for understanding crop growth and yield formation. However, challenges in field measurements, especially in assessing belowground biomass, hinder precise evaluation of the partitioning process.</div></div><div><h3>Objective</h3><div>This study developed a novel approach to estimate time series of partitioning coefficient (PC) using unmanned aerial vehicle (UAV) images.</div></div><div><h3>Methods</h3><div>Firstly, UAV-based remote sensing data was utilized to estimate leaf biomass growth (G_leaf), aboveground biomass growth (G_above), leaf area index (LAI), and leaf chlorophyll content (LCC). Next, total wheat growth (G_total) was estimated by integrating LAI and LCC into a photosynthesis model. Finally, the leaf partitioning coefficient (LPC) and aboveground partitioning coefficient (APC) were calculated by combining G_leaf, G_above, and G_total.</div></div><div><h3>Results</h3><div>The proposed method effectively captured the variability of partitioning coefficients (PCs) across different phenological stages and treatments, with a relative root mean square error (RRMSE) of 24 % between the estimated and measured average LPC (ALPC). The theoretical RRMSE for the estimated average APC (AAPC) derived from a synthetic dataset was 29 %. By incorporating the estimated PCs into a crop model, the simulation accuracy for aboveground biomass (AGB) and leaf dry matter weight (LDW) improved, achieving RRMSEs of 12 % and 11 %, respectively, while simulations based on default PCs in the APSIM model resulted in overestimation.</div></div><div><h3>Conclusions</h3><div>This study achieved a high-throughput estimation for the wheat partitioning coefficient.</div></div><div><h3>Implications</h3><div>The proposed approach holds promise for advancing our understanding of photo-assimilate partitioning.</div></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of sulfur and potassium foliar applications on wheat grain protein quality","authors":"","doi":"10.1016/j.fcr.2024.109639","DOIUrl":"10.1016/j.fcr.2024.109639","url":null,"abstract":"<div><h3>Context</h3><div>The effects of sulfur and potassium fertilizers on wheat yield and quality have been well studied, but most of them are used as basal fertilizers. However, the root system is senescent at the later stages of wheat growth and cannot absorb sufficient sulfur and potassium fertilizers plant needed. It is still unclear whether sulfur and potassium foliar applications at the later stages can affect wheat yield and quality.</div></div><div><h3>Objective</h3><div>This experiment was conducted to investigate the changes of sulfur and potassium accumulation and transport, protein synthesis and flour processing quality after foliar application of sulfur and potassium fertilizers, transport and the relating physiological mechanisms.</div></div><div><h3>Methods</h3><div>In 2020–2021 and 2021–2022, a three-factor split plot experiment was carried out in the middle and lower reaches of Yangtze River, with wheat variety, concentration of sulfur fertilizer and potassium fertilizer served as main factor, subfactor and sub-subfactor respectively.</div></div><div><h3>Results</h3><div>In the study from 2020 to 2022, the albumin protein content of both varieties decreased in the nutrient spraying treatment, particularly in the high potassium level. However, there was no significant effect on the globulin content. Moreover, the gliadin protein content decreased in the sulfur spraying treatment alone, but significantly increased the wheat gluten content, and thereby the total protein content. We also found significant genotypic differences in the composition and content of high molecular weight wheat glutenin subunits (HMW-GS) between the two varieties. The foliar spraying of sulfur and potassium fertilizers significantly increased the content of subunits 1 and 8 in Yangmai (YM15) and subunits 7 and 12 in Yangmai (YM16), and the effect of mixed spraying was better than single-nutrient spraying, especially the amount of 0.2 % sulfur and 0.3 % potassium fertilizer treatment.</div></div><div><h3>Conclusions</h3><div>The superimposed effect of sulfur and potassium effectively increased the total protein content by promoting the accumulation of sulfur in transit to the seeds, increasing the substrate supply level, and enhancing enzyme activity. Although sulfur and potassium combination can improve the grain protein quality and flour processing quality, too high spraying concentrations can decrease the flour processing quality.</div></div><div><h3>Implications</h3><div>Spraying the appropriate amount of 0.2 % sulfur and 0.3 % potassium fertilizer can serve as an optimization measure for high-quality and efficient production of different types of wheat varieties.</div></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142560964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biochar addition mitigates asymmetric competition of water and increases yield advantages of maize–alfalfa strip intercropping systems in a semiarid region on the Loess Plateau","authors":"","doi":"10.1016/j.fcr.2024.109645","DOIUrl":"10.1016/j.fcr.2024.109645","url":null,"abstract":"<div><h3>Objective</h3><div>Unbalanced competition for water poses a major challenge to intercropping systems in semiarid regions. The role of biochar as a soil amendment in regulating water balance and crop productivity is unclear.</div></div><div><h3>Methods</h3><div>In this two-year field trial, we investigated the impact of biochar application and method on the relationship between water balance utilization and productivity in maize–alfalfa strip intercropping. Monocropping [sole maize (SM) and sole alfalfa (SA)] and intercropping (I) systems were established, with biochar added to corresponding treatments (SMc, SAc, and Ic) and solely to intercropping alfalfa and maize (IAc and IMc).</div></div><div><h3>Results and conclusions</h3><div>Our findings reveal that the yield of the intercropping system (I) was 11.4 % higher than expected on average. Biochar addition significantly increased forage production and water use efficiency, with similar benefits observed in monocropping systems. While competition ratio (CR) values reduce also reducing competition between maize and alfalfa. In two years, applying biochar solely to alfalfa (IAc) resulted in a higher land equivalent ratio (LER) and water equivalent ratio (WER) of 8.63 % and 12.73 %, respectively, compared with applying biochar solely to maize (IMc). Notably, yield and water use efficiency (WUE) increased the most when biochar was applied to intercropped maize and alfalfa (Ic), increasing by 16.1 %–16.6 % and 6.7 %–10.3 % compared with I, resulting in an increase in economic benefits by 24.9 %–26.3 %. Different biochar application methods showed significant potential in mitigating water competition in intercropping, with both sole and joint applications improving WUE, with the latter (Ic) demonstrating the most pronounced effect. However, excessive soil water consumption poses risks of water overuse, emphasizing the need to balance biochar utilization with water resource management.</div></div><div><h3>Significance</h3><div>Our findings highlight the ability of biochar to alleviate water competition imbalances and optimize water use in intercropping, providing a new approach for efficient water use in semiarid rain-fed agricultural systems.</div></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142560966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Legume and maize intercropping enhances subsequent oilseed rape productivity and stability under reduced nitrogen input","authors":"","doi":"10.1016/j.fcr.2024.109644","DOIUrl":"10.1016/j.fcr.2024.109644","url":null,"abstract":"<div><div>Legume-inclusive cropping is increasingly appreciated for enhancing crop yield and sustainability. However, their impacts on subsequent oilseed rape productivity under reduced nitrogen (N) inputs have not been well explored. In a five-year field rotation experiment, oilseed rape was cultivated with N fertilizer at zero (MN0), recommended (MN100), and 35 % reduction (MN65) following maize monoculture or preceding lablab (<em>Lablab purpureus</em> (L.) Sweet) intercropping in addition to MN65 (IN65). The productivity and stability of subsequent oilseed rape, and relevant indices of soil fertility and N cycling enzymes were investigated. Compared with the MN0 control, the MN100, MN65 and IN65 treatments increased the rapeseed yield by 0.7- to 1.2-fold. Compared with MN100, MN65 decreased rapeseed yield by 21 % and N uptake by 16 % on average across years. However, preceding lablab intercropping (IN65) recovered yield and N uptake. Treatment IN65 increased soil total N content by 7 % and organic matter by 10 % compared to the monoculture treatments, corresponding to 18–25 % increase in the soil quality index by preceding pulse intercropping. Moreover, in parallel with the increase in soil urease activity, the soil nitrate content in IN65 markedly increased by 18–123 % compared with that in the MN65 or MN100 treatments at most stages of oilseed crop growth. Principal component analysis revealed that the IN65 treatment was well distinguished from the three monoculture treatments, which was attributed primarily to soil nitrate, organic matter, nitrate reductase activity, and microbial biomass N. This enhanced N turnover and availability, in turn, largely contributed to N uptake and yield recovery of subsequent rapeseed crops under reduced N input. Consequently, the yield sustainability and stability of rapeseed following lablab intercropping were greater than those following monoculture, as evidenced by the higher sustainability index (64 % vs. 49 %) and lower variation (20 % vs. 32 %). Overall, these findings indicate that lablab and maize intercropping enhances positive legacies for subsequent rapeseed productivity under reduced N inputs.</div></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142560965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pre-spike emergence nitrogen fertilizer application as a strategy to improve floret fertility and production efficiency in wheat","authors":"","doi":"10.1016/j.fcr.2024.109623","DOIUrl":"10.1016/j.fcr.2024.109623","url":null,"abstract":"<div><h3>Context or problem</h3><div>Effective nutrient management is critical for crop growth and development. However, using nitrogen-based fertilizers in agriculture raises substantial concerns about environmental pollution. The optimal timing for applying nitrogen to maximize floret fertility and production efficiency in wheat remains undetermined.</div></div><div><h3>Objective or research question</h3><div>This study investigated the optimal timing for N fertilizer application to enhance floret fertility and production efficiency in eastern Afghanistan's commonly cultivated Chonte#1 wheat variety.</div></div><div><h3>Methods</h3><div>A total of four experimental sets were conducted at Nangarhar University Faculty of Agriculture and Bihsood district during the 2019–2022 growing seasons. The first-year experiment consisted of two treatments: (1) control (no fertilizer) and (2) fertilized. The second and third-year experiments comprised four treatments, including (1) control (no fertilizer added), (2) basal dressing at the tillering stage (BDTS), (3) BDTS+light top-dressing (LD), and (4) BDTS+heavy top-dressing (HD) applied two weeks before spike emergence.</div></div><div><h3>Results</h3><div>The results indicated that the application of N topdressing had a significant (P&lt;0.05) effect on the SPAD value and floret fertility percentage. In contrast, SPAD values showed a positive relationship with floret fertility rate and yield components but negatively correlated with unfilled grain per spike. The use of BDTS+LD treatment significantly increased spike length, spike weight, number of spikelets per spike, and filled grain per spike compared to the control. The number of unfilled grains ranged from 6.4 % to 51.9 % between the control and N application. The 1000-grain weight, number of spikes per m^–2, and floret number per m^–2 were also significantly higher in the N top-dressed groups. In the first experiment, fertilized treatment showed a 28.3 % increase in yield per m^–2. Meanwhile, in the second experiment, the yield range varied among the treatment groups compared to the control group, ranging from 30.7 % to 66.8 %.</div></div><div><h3>Conclusion</h3><div>The application of N two weeks before spike emergence in wheat significantly improved floret fertility and production efficiency and led to the increment of final yield.</div></div><div><h3>Implications</h3><div>The findings suggest that prior spike emergence nitrogen fertilizer application is crucial for maximizing floret fertility and yield, offering a potential strategy for farmers to enhance production efficiency.</div></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing water and nitrogen management to balance greenhouse gas emissions and yield in Chinese rice paddies","authors":"","doi":"10.1016/j.fcr.2024.109621","DOIUrl":"10.1016/j.fcr.2024.109621","url":null,"abstract":"<div><h3>Context</h3><div>Irrigation and fertilizer applications, the two most common practices to ensure high yield, affect almost all soil biogeochemical processes including greenhouse gas (GHG) emissions. How to balance irrigation and nitrogen application in farmland to synergize GHG emissions and crop yield is an inherent requirement for achieving sustainability, particularly in China rice paddy fields.</div></div><div><h3>Objective</h3><div>In this study, we first acquired data on GHG emissions and crop yield from rice field experiments worldwide under various irrigation and nitrogen application conditions. Subsequently, based on this dataset, we conducted modeling analysis using machine learning techniques to assess the optimization potential of irrigation and nitrogen fertilizer application in Chinese rice fields, aiming to achieve synergistic reductions in GHG emissions and improvements in crop yield under both historical and future climate scenarios.</div></div><div><h3>Results and conclusions</h3><div>The results indicated that the selected input features provided good predictive accuracy for rice yield and Global Warming Potential (GWP) in rice fields, with R² of 0.71 and 0.85, respectively. Furthermore, upon optimizing irrigation water usage in China rice fields to concurrently address GHG emissions and crop yield, the potential reductions in irrigation water were found to be −21.5 %, −29.1 %, and −13 % under past climate conditions, the SSP126 scenario, and the SSP585 scenario, respectively. After jointly optimizing both irrigation water and nitrogen fertilizer application, the reduction in irrigation water under past climate conditions, the SSP126 scenario, and the SSP585 scenario were −23 %, −31.4 %, and −16.9 % respectively. Correspondingly, the reductions in nitrogen fertilizer application were −22.9 %, −27.3 %, and −24.84 % for each scenario. Additionally, the study revealed a significant regional disparity between the northern and southern regions of China in these optimizations. Overall, southern China exhibits greater potential for irrigation water savings and rice yield increases compared to northern regions, while the potential for greenhouse gas emission reduction is higher in the north.</div></div><div><h3>Significant</h3><div>The findings provided both direction and quantifiable data support for the sustainable production of rice.</div></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Responses of yield, CH4 and N2O emissions to ratoon rice cropping and different management practices","authors":"","doi":"10.1016/j.fcr.2024.109622","DOIUrl":"10.1016/j.fcr.2024.109622","url":null,"abstract":"<div><h3>Context or problem</h3><div>Conversion from single rice (SR) or double rice (DR) to ratoon rice (RR) is gaining growing popularity in China. Yet, a quantitative synthesis of their impact on greenhouse gas (GHG, including methane (CH₄) and nitrous oxide (N₂O)) emissions and grain yield has not been conducted.</div></div><div><h3>Objective or research question</h3><div>The objective was to evaluate the effects of conversion from SR or DR to RR on CH₄ and N₂O emissions, grain yield, global warming potential (GWP), and greenhouse gas intensity (GHGI) and to investigate the potential responses to different operating practices [alternate wetting-drying irrigation, nitrogen management, rice variety selection, and their multiple treatments (multiple measures)] in RR fields (oRR).</div></div><div><h3>Methods</h3><div>In this study, a comprehensive meta-analysis of 571-paired measurements from ratoon rice fields was conducted.</div></div><div><h3>Results</h3><div>Our results showed that the conversion from SR to RR significantly increased CH₄ emissions, grain yield, and GWP by 35.4 %, 30.6 %, and 43.3 %, respectively. In contrast, the conversion from DR to RR decreased CH₄ emissions, grain yield, and GWP by 23.2 %, 7.4 %, and 30.0 %, respectively. Interestingly, both conversions from SR or DR to RR did not affect N₂O emissions but reduced GHGI in paddy fields, suggesting that RR provided an economically and ecologically sustainable rice planting model. Furthermore, on average, oRR further decreased CH₄ and N₂O emissions and GHGI from RR fields but did not affect grain yield. Among the existing management practices, the overall effect of multiple measures was better than that of alternate wetting-drying irrigation, nitrogen management, and rice variety selection.</div></div><div><h3>Conclusions</h3><div>Overall, ratoon rice cropping decreased CH₄ emissions and maintained rice grain yield. However, it is also necessary to further implement comprehensive cultivation strategies in the future to maximize the benefits of grain yield and GHG emissions reduction.</div></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wheat genetic progress in biomass allocation and yield components: A global perspective","authors":"","doi":"10.1016/j.fcr.2024.109617","DOIUrl":"10.1016/j.fcr.2024.109617","url":null,"abstract":"<div><h3>Background</h3><div>Wheat is an essential food source and is subjected to intense breeding efforts for increased grain yield, but stagnation in grain yield improvements has been reported in many regions. The identification of genetically linked factors impeding further progress in wheat grain yield improvement is therefore urgently required.</div></div><div><h3>Method</h3><div>A comparative meta-analysis of data from 66 publicly available field experiments involving multiple wheat genotypes was performed to identify traits altered in breeding programs, their relationship with grain yield, and their past and current impact on grain yield increases.</div></div><div><h3>Results</h3><div>Wheat grain yield can be increased by increasing either the aboveground biomass (ABM) or the harvest index (HI). However, there was no correlation between these traits since a reduction in plant height can occur with increases in the HI and overall grain yield, but with no reduction in the ABM. The combined data from 32 global datasets revealed a substantial increase in wheat grain yield from 1860 to 2017, accompanied by improvement in HI and yield components. When considering only the genotypes introduced from the 1960s to 2017, there was a linear increase observed in both grain yield and HI until the mid-1980s. However, genetic progress in HI and GY has slowed down since then. Before the mid-1980s, there was a decreasing trend observed in plant height which remained relatively static thereafter. While ABM did not exhibit significant increases during this period. After the mid-1980s, significant improvements have been observed in ABM; however, no obvious increase were observed in other yield components.</div></div><div><h3>Conclusions</h3><div>Since the 1980s, there has been an increase in the aboveground biomass of wheat, while grain weigth and grains per m² increases trending slowly, and both harvest index and grain yield have almost stagnated. Therefore, increasing grains per m² and/or grain weight should be the major research direction to further improve the wheat harvest index and grain yield in the future.</div></div><div><h3>Implications</h3><div>The systematic study of changes in wheat traits in past breeding efforts for improved grain yields has provided useful indicators for the direction of wheat breeding in the future.</div></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142536174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variations in water availability and N cycling across different seasons in cover crop systems","authors":"","doi":"10.1016/j.fcr.2024.109608","DOIUrl":"10.1016/j.fcr.2024.109608","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Context&lt;/h3&gt;&lt;div&gt;Cover crops (CCs) exert significant influences on both soil water content (SWC) and nitrogen (N) cycling, with their effects often varying across different stages of crop succession. Many research endeavors overlook this seasonal variability by focusing solely on single sampling time points.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Objective&lt;/h3&gt;&lt;div&gt;This study seeks to explore how the introduction of diverse CCs influences the seasonal fluctuations of soil nitrate nitrogen (NO&lt;sub&gt;3&lt;/sub&gt;-N) and biological (soil N functional genes – NFGs) components of the N cycle, SWC, and cash crop yield over a three-year maize-soybean succession in northeastern Italy.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Methods&lt;/h3&gt;&lt;div&gt;Three CC management systems were compared: a fixed treatment with triticale; a 3-year succession of rye, crimson clover, and mustard; and a weedy fallow as control. Soil N cycling was assessed using real-time PCR and Ion Chromatography, SWC through Sentek’s Diviner2000.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;CCs had no impact on cash crop yields and did not display water competition with subsequent cash crops compared to the weedy fallow. At CCs termination, grasses decreased soil NO&lt;sub&gt;3&lt;/sub&gt;-N content (as catch crops) while enhancing potential microbial N-fixing activity (&lt;em&gt;nifH&lt;/em&gt;), whereas clover led to the highest residual NO&lt;sub&gt;3&lt;/sub&gt;-N and potential N nitrification (AOA). Agronomic operations likely mitigated differences in NFG abundances following CC residue incorporation. During the cash crop season, clover, mustard, and weeds (including wild legumes) were estimated to release higher amounts of N according to the CC-NCALC model, compared to rye and triticale which exhibited immobilization. Nonetheless, consistent N nitrification and denitrification potentials were observed across all treatments except for weedy fallow, with higher NFG abundance when soybean was cultivated instead of maize, underscoring the influence of cash crop species on N transformation dynamics.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Conclusions&lt;/h3&gt;&lt;div&gt;CC and cash crop species, seasonality of crops sequence, and management operations represent pivotal factors shaping the soil N cycling dynamics intricately governed by N-cycling microbial communities and the temporal variability of the SWC. Upon CC termination, grass CCs decrease soil NO&lt;sub&gt;3&lt;/sub&gt;-N content, whereas clover CC sustain high NO&lt;sub&gt;3&lt;/sub&gt;-N content, enhancing microbial nitrification. Agronomic operations disrupt differences in N processes subsequent to the incorporation of different CCs. However, all CC residues enhance microbe-mediated nitrification and denitrification by cash crop harvest time, potentially more pronounced in the presence of soybean cash crop compared to maize.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Significance&lt;/h3&gt;&lt;div&gt;The substantial seasonal variability observed emphasizes the necessity of carefully timing sample collection within a crop succession (e.g., at CC termination) for effectively utilizing NFGs and chemical","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}